Final answer:
The countries highlighted in BLUE represent the Allied Powers, which were in opposition to the Axis Powers during World War II.
Step-by-step explanation:
The World War II group represented by the countries highlighted in BLUE is the Allied Powers. During World War II, the Allied Powers mainly included the United States, the Soviet Union, and Britain. These nations were in opposition to the Axis Powers, notably Germany, Japan, and Italy.
The Allied Powers worked in unison to ultimately achieve victory in the war. It's important to clarify that while the Central Powers were the adversaries of the Allies in World War I, the Axis Powers were the equivalent opponent group in World War II.